Drill head or bit



April 1%, 1956 T. s. HALLETT 2,742,439

DRILL HEAD OR BIT Filed July 27 1953 THOMAS S. HALLETT INVENTOR BY $08MATTORNEY United States Patent DRILL HEAD OR BIT Thomas S. Hallett,Calgary, Alberta, Canada Application July 27, 1953, Serial No. 370,547Claims. (Cl. 255-312) The present invention relates to a drill head orbit and it consists in the combinations, constructions and arrangementsof parts herein described and claimed.

Generally the invention relates to a drill head or bit which isparticularly adaptable for the drilling of rock, coal and other mineralsand which includes a pair of cutter wheels which are so positioned andshaped that they are caused to revolve upon their axes when the drillhead or bit is rotating, thus presenting a plurality of cutting surfacesto the walls and base of the hole being drilled. One of the features ofthe invention is the provision of means whereby the various parts of thedevice may be removed and/ or replaced.

An object of the invention is the provision, in a device of thecharacter set forth, of a pair of novel centering or positioning conesforming a ,partof the invention.

Another object of the invention is to provide a device of thecharacterset forth in which the various parts are easily removed andreplaced as desired.

Another object of the invention is to provide, in a device of thecharacter set forth, a pair of interlocked cutting wheels of novelconstruction and forming a part of the invention.

A further object of the invention is to provide, in a device of thecharacter set forth, novel retaining pins forming a part of theinvention.

Another object of the invention is to provide, in a device of thecharacter set forth, a novel pull washer and associated spring bothforming parts of the invention.

Other and further objects of the invention will become apparent from areading of the following specification taken in conjunction with thedrawing, in which:

Figure l is a side elevational view of an embodiment of the invention,

Figure 2 is a view taken at right angles to Figure 1 and showing thedevice in a hole being drilled thereby and attached to a conventionaldrill rod,

Figure 3 is an exploded elevational view certain elements of theinvention,

Figure 4 is a plan view of a part of the invention,

Figure Sis an exploded elevational view illustrating a cone and spindleboth forming parts of the invention,

Figure 6 is an enlarged longitudinal sectional view of a cutter wheelforming a part of the invention, and

Figure 7 is a plan view ilustrating certain elements of the inventionand their corelation as viewed, for example, along line 7--7 of Figure1.

Referring more particularly to the drawing, there is shown therein thelower end of a conventional drill rod 10 which is rotatable at thesurface by conventional means (not shown). A frame is generallydesignated at 11 and is provided with a horizontally extending flatupper surface 12 from which extends upwardly and cen-. trally acylindrical member 13 which, in turn, has extending upwardly therefroman externally threaded projection 14 which is adapted to be threadedinto the lower end of the rod 10, as indicated at 15 in Figure 2.

illustrating pull washer forming a 2,742,439 Patented Apr. 17, 1956 and18 is substantially centrally bifurcated as indicated at 19 and 20,respectively, to provide therein legs 21 and 21a in the leg portion 17and legs 22 and 23 in the leg portion 18. The outer face of the leg 21aand the outer face of the leg 22 are both machined so that they inclineinwardly and downwardly as clearly shown, for example, in Figure 1 ofthe drawing and the openings 19 and 20 are provided with sides which lieparallel to their respective inclined faces, the latter being shown at24 and 25.

A pair of spindles each of which is generally designated at 26 isprovided and one of such spindles extends through the lower portions ofthe legs 20 and 21 while the other spindle 26 extends in an oppositedirection through the legs 22 and 23 and it'will be seen that each ofthe spindles is positioned at right angles to one of the faces 24 and25.

Each of the spindles 26 is provided with an elongated cylindrical bodyportion 27 one end portion 28 of which is enlarged and provided at itsouter end with a conical termination 29. The conical termination 29provides, with the enlarged portion 28, a shoulder 30.

A frusto-conical member 31 is revolubly mounted upon the enlargedportion 28 and may, if desired, be provided with a ball race 32 tolessen the frictional contact thereand encircling the 34which areadaptedto extend vertically downwardly through the legs 21, 21a, 22 and23. Each of the body portions 27 of the spindles 26 is provided upon itsupper 'side with a pair of longitudinally spaced recesses 36.

Revolubly mounted upon each of the spindles 26 between the legs 21 and21a and the legs 22 and 23, respectively, and extending in oppositedirections as clearly shown in Figure 7, is a cutter wheel which isgenerally designated at 37. Each cutter Wheel 37 is provided with a hub38 and a plurality of curvular teeth 39 having sharpened outer edges 40.A compression spring 41 surrounds the cylindrical portion 13 and bearsagainst the upper face of the washer 32' at one of its ends and againstthe underside of the rod 10 at its other end.

It will be seen that the device may be quickly and easily assembled ordisassembled by first placing the frustoconical member 31 upon theenlarged portion 28 of its respective cylinder and thereafter insertingthe spindles 27 through the legs 21 and 21a and through the legs 22 and23 in opposite directions while at the same time mounting the cuttingwheels in opposite directions upon such spindles between the aforesaidpairs of legs. When the cutting wheels are thus assembled, it will beapparent that the outer faces of the teeth 39 will interengage. The pins34 may then be inserted through the openings 33 until the heads 35thereof lie within such openings and the lower ends of such pins engagewithin the recesses 36 in the spindles 26. The spring 41 may then bemounted over the cylindrical member 13 and the threaded member 14engaged in the lower end of the rod 19 whereupon the spring 41 will becompressed and will bear against not only the upper face of the washer32 but also against the heads 35 of the pins 34 to thus ensure thepositive engagement of the pins 34 with the spindles 26 whereby toprevent the accidental removal of such spindles and their attacheddevices.

Inoperation, it will be apparent that the thus assem-' action upon thebottom 43 of a hole 44 in which the device is mounted and that, due tothe inclination and dishing of the two cutter wheels 37 together withthe interlocking relationship one with the other, that the wheelsrevolve upon their respective spindles as the device is rotated. It willbe also apparent that the members 29 and 31 together forming cones(which are externally serrated as illustrated, for example, in Figures 1and 7) will follow their respective cutter wheels as the bit revolves,absorbing the back thrust of the wheels and holding them in their propercutting position and at the same time acting as reamers to true theinner circumference of the drill role to thereby keep the drill bitcentrally located in the drill hole.

Reference to Figure 2 of the drawing will show a relatively small core45 formed centrally upon the bottom 43 of the hole 44' which core 45will build up to the point of engagement between the two cutter wheels37 and also at that time act as a centering device for the location ofthe drill head or bit within the hole 44.

While but one form of the invention has been shown and described herein,it will be readily apparent to those skilled in the art that many minormodifications may be made without departing from the spirit of theinvention or the scope of the appended claims.

What is claimed is:

1. A device of the character described comprising a frame bifurcated toprovide a pair of dependent portions, said portions each beingbifurcated to provide a pair of dependent legs, a spindle extendingthrough each pair of legs, a toothed cutter wheel revolubly mounted uponeach spindle between its respective pair of legs, said toothed cutterwheels being enmeshed with each other, a conical terminal member formedintegrally with an outer end of each of said spindles, and afrusto-conical 4 member revolubly mounted on each spindle adjacent itsrespective terminal and forming a substantial continuation of saidterminal, said spindles each extending in an inclined direction withrespect to the vertical axis of the frame.

2. A device as defined in claim 1 wherein said cutter wheels eachcomprise a dished disc, and wherein a plurality of spaced cutting teethare formed on the peripheral portion of each disc, said teeth acting ascutting members and as engaging teeth for said meshing of one cutterWheel with the other.

3. A device as defined in claim 1 wherein the effective cutting diameterof said wheels is at least as great as the effective operating diameterof said cones.

4. A device as defined in claim 1 wherein said spindles are removablymounted in said frame, and wherein means is provided for locking saidspindles against rotation.

5. A device as defined in claim 4 wherein said means includes a drillrod, an upwardly extending portion for said frame threadably affixed inthe lower end of said rod, a pair of recesses in the upper side of eachspindle, pins each extending vertically through said frame and eachreceivable in one of said recesses, a shoulder formed in the upper endof said frame, a washer mounted on said frame and bearing against theupper face of said shoulder, and a compression spring surrounding saidupwardly extending portion of the frame and bearing against the upperface of said washer and the lower end of said rod.

References Cited in the file of this patent UNITED STATES PATENTS1,867,545 Akeyson July 19, 1932 1,939,131 Montgomery et al Dec. 12, 19332,068,327 Howard et a1. Jan. 19, 1937

1. A DEVICE OF THE CHARACTER DESCRIBED COMPRISING A FRAME BIFURCATED TOPROVIDE A PAIR OF DEPENDENT PORTIONS, SAID PORTIONS EACH BEINGBIFURCATED TO PROVIDE A PAIR OF DEPENDENT LEGS, A SPINDLE EXTENDINGTHROUGH EACH PAIR OF LEGS, A TOOTHED CUTTER WHEEL REVOLUBLY MOUNTED UPONEACH SPINDLE BETWEEN ITS RESPECTIVE PAIR OF LEGS, SAID TOOTHED CUTTERWHEELS BEING ENMESHED WITH EACH OTHER A CONICAL TERMINAL MEMBER FORMEDINTEGRALLY WITH AN OUTER END OF EACH OF SAID SPINDLES, AND AFRUSTO-CONICAL MEMBER REVOLUBLY MOUNTED ON EACH SPINDLE ADJACENT ITSRESPECTIVE TERMINAL AND FORMING A SUBSTANTIAL CONTINUATION OF SAIDTERMINAL, SAID SPINDLES EACH EXTENDINNG IN AN INCLINED DIRECTION WITHRESPECT TO THE VERTICAL AXIS OF THE FRAME.